JPH0610532Y2 - Spindle for magnetic recording / playback device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a spindle used in a magnetic recording / reproducing apparatus for holding a magnetic sheet detachably.

[Prior art]

In a magnetic recording / reproducing apparatus using a magnetic sheet as a recording medium, a spindle driven by a motor is provided, and the magnetic sheet is detachably attached to this. In the current magnetic recording, high density magnetic recording is required, and therefore the track width is extremely narrow, for example, 0.06 mm. When the track width is narrow as described above, even if the spindle is slightly eccentric, off-track occurs, so that the recorded data cannot be reproduced. Therefore, extremely high precision is required for machining the spindle.

In the conventional spindle, the spindle core portion and the flange portion are integrally machined from metal (brass, stainless steel, etc.). The spindle core part is the part where the center core of the magnetic sheet fits around its outer periphery, which requires extremely high processing accuracy in order to prevent off-track due to eccentricity, and reduces abrasion due to rubbing with the center core due to attachment and detachment of the magnetic sheet. Therefore, it is necessary to use a material having high hardness and wear resistance. On the other hand, the flange portion has a claw portion protruding upward on the outer periphery thereof, and the claw portion supports the lower surface of the center core, and although it has a complicated shape, it has a high hardness and durability like the spindle core portion. It does not require wear resistance.

However, in the conventional spindle, since the spindle portion and the flange portion are machined together, a spindle having a complicated shape must be formed with high accuracy by using a material having hardness and wear resistance required for the spindle core portion. Since it is difficult to process, the number of man-hours is large in order to perform high-precision processing which is difficult, and the yield is deteriorated, and the cost is inevitably high.

[Purpose of device]

The present invention is a highly accurate, reliable and inexpensive magnetic recording /
An object of the present invention is to provide a spindle of a reproducing device.

[Constitution of device]

In order to achieve the above object, the present invention divides a spindle core and a flange, and forms the spindle core with a hard and wear-resistant material such as stainless steel, and the flange is relatively soft and has good workability, for example. It is made of a material such as plastic such as polyacetal or aluminum alloy, and is fixed to form a spindle.

〔Example〕

FIG. 1 is an exploded view of the spindle of the present invention. The spindle core 1 is composed of a shaft portion 2 and a collar 3 formed under the shaft portion 2, and is made of a hard metal such as stainless steel. The shaft portion 2 has a shaft hole 2a formed in the center thereof, into which a rotary shaft of a motor is fitted, and a center core of a magnetic sheet is detachably fitted to the outer periphery of the shaft hole 2a.

The flange 5 is composed of a bottom portion 6 and a tubular portion 7, and is made of a relatively soft material such as plastic such as polyacetal or aluminum. The bottom portion 6 is formed with a shaft hole 6a which is fitted into the shaft portion 2 of the center core 1, and the upper end of the cylindrical portion 7 is formed with a plurality of claws 7a for supporting the center core of the article sheet. ing. A ring-shaped permanent magnet 8 is housed inside the cylindrical portion 7 and is fixed with an adhesive 9 (see FIG. 2).

FIG. 2 shows the use state of the spindle of the present invention.

The magnetic sheet jacket 20 includes a rectangular jacket 21 and a magnetic sheet 22 rotatably housed therein.
It consists of and. An opening 24 into which the magnetic head 23 is inserted is formed in the jacket 21. A center core 25 made of plastic is attached to the center of the magnetic sheet 22, and a hole 25a for fitting the spindle core 1 is formed in the center core 25. A metal plate 2 made of a metal having a high magnetic permeability, for example, permalloy, is provided below the center core 25.
6 is fixed and attracted and held by the magnetic flux of the permanent magnet 8.

When mounting the magnetic sheet 22, the center core 25 is detachably fitted to the shaft portion 2 of the spindle core 1. And
The metal plate 26 provided on the lower surface of the center core 25 is supported by the claws 7 a of the flange 5 and is attracted and held by the magnetic flux of the permanent magnet 8. When the motor 12 rotates at a high speed, the chucked magnetic sheet 22 rotates, and the magnetic sheet 22 is rotated.
During the rotation of, data is recorded on the recording surface by the magnetic head 23.

The mechanical performance required for the spindle is the runout of the spindle core portion and the runout of the portion 7a of the flange that receives the center core of the magnetic sheet. The runout of the spindle core causes off-track at the time of recording / reproducing, and the surface runout of the flange portion 7 causes the vibration of the magnetic sheet, which adversely affects the head touch.

However, according to the present invention, since the spindle core portion has a simple cylindrical shape, highly accurate machining can be performed relatively easily.

The assembly of the spindle according to the present invention will be described below.

The spindle core 1 is fitted on the rotary shaft 13 of the motor 12. Since the spindle core 1 can be machined with high accuracy as described above, the core deviation of the spindle core due to the rotation of the motor 12 in this state is very small. With the grindstone rotating while rotating the spindle core 1 with the motor 12,
The outer periphery of the shaft portion 2 is brought into contact with each other for grinding. In this case, the rotation torque of the motor 12 is extremely small in the magnetic camera system, and since the spindle core 1 is a difficult-to-cut material such as stainless steel as described above, large grinding cannot be performed, but on the order of several μm. Even by minute grinding, the original spindle core 1 is highly accurate, and thus the runout can be sufficiently removed.

Next, the flange 5 is fitted to the spindle core 1. Also in this case, it is necessary to suppress the surface deflection of the 7a portion of the flange 5 within about 10 μm in order to obtain a stable head touch.

Since the flange 5 is also relatively easy to machine, it is easy to obtain high accuracy, and the surface wobbling of the flange 5 when fitted to the spindle core 1 is not so large. However, as described above, the flange 5 is made of a material such as plastic or aluminum that can be easily processed. Therefore, it is easy to fix the motor 12 and additionally rotate the 7a portion of the flange 5 to remove the surface runout. It can be done in a short time.

Further, the spindle core and the flange may be press-fitted, but since the shaft portion 2 of the spindle core processed with high precision is damaged, the spindle core 1 may have a structure in which only the press-fitting portion has a step, or FIG. Spindle core 1 as shown in
The flange 5 is fitted to the motor 12 in which the spindle core 1 is attached to a jig 102 having a high-precision hole portion 101 into which a hole is inserted and a surface 103 which receives the 7a portion of the flange 5 which is perpendicular to the hole portion 101. Set the motor 12 and position the spindle core 1 and the flange 5 so that the adhesive 1
It can also be fixed at 04.

[Effect of device]

According to the present invention having the above-mentioned configuration, the spindle which has been conventionally integrated is divided into a spindle core and a flange. Since it is made of a material that is relatively soft and easy to cut and grind, it is possible to add the spindle core to the rotary shaft of the motor after the spindle core is fitted to the spindle core if necessary. As for the supporting flange, it is possible to easily perform additional machining even after it is fitted to the spindle core that has been processed with high precision, so it is possible to obtain a spindle for magnetic recording / reproducing device with high accuracy without core runout or surface runout. it can. Further, since the process of fitting the spindle core to the rotating shaft of the motor and the process of fitting the flange to the spindle core can be separated and the accuracy control can be performed in each process, it is possible to perform high efficiency work. Accurate spindle can be obtained.

[Brief description of drawings]

 FIG. 1 is an exploded perspective view showing an embodiment of the present invention. FIG. 2 is a sectional view showing a usage state. FIG. 3 is a sectional view showing a mounted state. 1 ... Spindle core 2 ... Shaft part, 3 ... Collar 5 ... Flange, 6 ... Bottom part 7 ... Cylindrical part, 7a ... Claw 8 ... Permanent magnet, 9 ... Adhesive material 21 ... Jacket, 22 ... Magnetic sheet 23 ... Magnetic head, 25 ... Center core 26 ... Metal plate.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Shinichi Matsuda 1-324 Uetakecho, Omiya City, Saitama Prefecture Fuji Photo Koki Co., Ltd. (56) Reference JP 58-35772 (JP, A) Sho 59-112385 (JP, U)

Claims (1)

[Scope of utility model registration request] 1. A spindle core made of a hard metal which is separately fitted to a rotary shaft of a motor, and a plastic or aluminum which is fitted to the spindle core through a shaft hole having an inner diameter substantially equal to the outer diameter of the spindle core. Made of a soft material made of a flange, the lower part of the spindle core is formed with a flange having a diameter larger than that of the shaft hole, and the lower surface of the flange abuts, and the upper surface of the flange has a magnetic sheet. A spindle for a magnetic recording / reproducing apparatus, characterized in that a supporting surface for supporting a lower surface of a center core fixed to the central part of the is formed integrally.